If you read enough supplement advertisements, like I do, you’ll often see the purity of a product often cited as one of its merits. It’s usually some phrase like:

Contains no binders! No fillers! No colours! No excipients! No starch! No gluten! No coatings! No flow agents!

It’s a point of pride for supplement manufacturers to advertise that their product contains nothing but the labelled ingredient. And that’s also seen as an important benefit to many that purchase supplements. The perception from many consumers (based on my personal experience) seems to be that products are inferior if they contain non-drug ingredients. By this measure, drug products are problematic. Pharmaceuticals all contain an array of binders, coatings, supplements and fillers. Even (gasp) artificial ingredients and sweeteners! And they’re often, though not always, disclosed on the package label.

But rather than being a negative feature, these supplementary, non-medicinal ingredients play a critical role in ensuring that drug products are of consistent and reproducible quality. Without them, we’d have products that are potentially unstable, we’d be unclear if they were actually being absorbed, and we wouldn’t know if they actually delivered any active ingredients into the body. In short, we’d be in the same situation we’re currently in with many herbal remedies and other types of supplements.